New Zealand Subregion

a floristic and zoogeographic subregion comprising the South and North islands of New Zealand, the Chatham Islands, Macquarie Island, the Auckland Islands, and several other islands lying approximately between 29° and 54° S lat.

The New Zealand floristic subregion (or region), one of the distinctive botanical-geographic subdivisions of the earth’s dry land, is part of the Palaeotropical Region, or Southern Floristic Realm. The climate is oceanic and subtropical in the north and moderate to cool-moderate in the south. The flora includes more than 1,800 species of higher plants, which differ markedly owing to variations in climate, geological structure, and history. Although there are only about 30 endemic genera and no endemic families, more than three-fourths of the species are endemic. There are many adventive plants. The predominant families are the Compositae, constituting more than 14 percent of all species, Scrophulariaceae, Gramineae, Cyperaceae, Umbelliferae, Orchidaceae, Ranunculaceae, and Rubiaceae. There are many ferns, including large treelike ferns, epiphytes, and lianas. Among the largest genera are Veronica (subgenus hebe); Celmisias, Olearia, and Senecio of the family Compositae; Coprosma of the family Rubiaceae, and Carex of the family Cyperaceae. The forests are dominated by endemic species of the genera Nothophagus, Podocarpus, Dacrydium, and Phyllocladus. The flora of New Zealand has developed in isolation since the Miocene. It is genetically related to the flora of the extreme southern part of South America (through Antarctica in the distant past) and southeastern Australia. It has even more remote ties with the flora of the northern hemisphere.

The New Zealand zoogeographic subregion is a subregion of the Australian zoogeographic region, although it is sometimes considered an independent zoogeographic region. The fauna is relatively sparse and has all the characteristics of island fauna. Excluding the species introduced by man, mammals are represented by only two endemic species of bats. There are more than 200 species of birds, many of them endemic. Sea birds, such as penguins, petrels, cormorants, and gulls, are numerous. Flightless birds include the kiwi, several rails (such as the weka), and the moa, which was exterminated in the late 18th and early 19th centuries. The kakapo has almost entirely lost its ability to fly. Flying birds are represented by flycatchers, warblers, nuthatches, tits, and starlings. A harmful bird is the kea, a parrot of the genus Nestor, which tears open the backs of sheep.

Among reptiles there are endemic genera and species of skinks and geckos. The most characteristic reptile is the tuatara. The only amphibian is a frog of the genus Leiopelma. Freshwater fish are poorly represented, and most have evolved from marine species. There is one species of eel, and the most common fish belong to several species of the family Galaxiidae. The numerous insects include about 1,000 species of butterflies, primarily nocturnal. There are no scorpions. Land mollusks are common, and the species attest to the existence of an ancient (pre-Mesozoic) continental link between New Zealand and Australia, certain Pacific islands, and South America (through Antarctica).

In the last century the fauna of the New Zealand subregion has been enriched by a large number of acclimatized mammals (deer, chamois, foxes, rabbits), birds (chaffinch, goldfinch, greenfinch), and representatives of other classes (trout) which in many cases have multiplied rapidly and are now supplanting indigenous species.